The concept of a combination calculator-watch is not new and has produced a wide variety of configurations. Most of the various attempts to formulate such a calculator and watch combination have resulted in the use of digital format and a conventional calculator type numerical button layout. Such watches also conventionally employ a visible liquid crystal screen area in which the digits and their manipulation are displayed together with vertical and horizontal rows of numerical input and function buttons arranged adjacent that display. This type of arrangement of columns is shown in U.S. Pat. No. 4,266,278.
Exemplary of additional types of digital watch and integral calculator arrangements, where the calculator function buttons are arranged about the watch housing and about a digital display are shown in Nakamura et al, U.S. Pat. No. 4,055,755, Nakagiri et al, U.S. Pat. No. 4,268,913, and Maeda et al, U.S.Pat. Nos. 4,120,036 and 4,300,204.
In the Maeda et al '036 and '204, and Nakagiri et al '913 patents, a plurality of function buttons are positioned in a generally circular pattern about a display and on the front of the watch case housing. In Maeda et al, eighteen separate inputs are arranged about the watch face. Four inputs are arranged across the top and bottom of the display with five inputs separately arranged on each side. The function buttons for addition, subtraction, multiplication and division are positioned across the top of the watch housing above the display with the equal and day function buttons, together with the zero, one and two inputs being on the right hand side. The clear entry, decimal point, nine, eight and seven buttons are located on the left hand side of the display and the three, four, five and six numeral buttons are located across the bottom of the display.
In Nakagiri et al ('913), twenty-two separate inputs are arranged around the display. At the very top of a switch 80-1 is used to switch between a calendar and a time display functions. From one o'clock down to four o'clock, function buttons are provided corresponding to square root, division, times, minus, plus, equals and a decimal point. A button corresponding to the numeral one is positioned adjacent the nine o'clock position and a button corresponding to numeral zero lies adjacent five o'clock with the remaining numerals extending in ascending order from nine o'clock to five o'clock or in a counterclockwise arrangement relative to clockwise hour designations. Additional function buttons then extend from ten o'clock to eleven o'clock.
In Nakamura et al ('755), a digital display is provided in the center of the watch face and positioned thereabout are a plurality of touch electrodes, thirteen in number. The patent does not indicate what particular items or inputs are dedicated to each touch electrode and a separate mode switch is provided in the side wall of the watch frame for selecting between time and calculation operations.
In Tanaka et al ('004), a waterproof terminal arrangement is disclosed and in FIG. 4, a plurality of function switches are again provided about a circular digitized display. The zero input button is located adjacent the normal nine o'clock position with buttons for numerals 1-9 thereafter extending in a counterclockwise fashion around to a position for numeral 9 located approximately at the three o'clock position. The remaining arc about the watch includes function buttons for plus, minus, divide, square root, log and cancel inputs.